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Metabolic syndrome and uric acid nephrolithiasis
Khashayar Sakhaee1, Naim M Maalouf
1Charles & Jane Pak Center for Mineral Metabolism and Clinical Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-8885, USA. Khashayar.sakhaee@utsouthwestern.edu
Seminars in Nephrology
|March 25, 2008
Summary
Metabolic syndrome increases uric acid kidney stone risk due to overly acidic urine. This acidity stems from increased net acid excretion and impaired ammonium buffering, potentially linked to kidney insulin signaling changes.
Area of Science:
- Nephrology
- Metabolic Disorders
- Urology
Background:
- Metabolic syndrome is a cluster of conditions increasing type 2 diabetes and cardiovascular disease risk.
- Uric acid nephrolithiasis prevalence is higher in patients with metabolic syndrome features like obesity and diabetes.
- Abnormally low urinary pH is a key factor in developing idiopathic uric acid stones.
Purpose of the Study:
- To review epidemiologic and metabolic studies linking uric acid nephrolithiasis with metabolic syndrome.
- To examine potential mechanisms causing unduly acidic urine in these conditions.
- To explore emerging links between urinary acidity defects and kidney insulin signaling.
Main Methods:
- Review of epidemiologic studies.
- Analysis of metabolic studies.
- Examination of proposed pathophysiologic mechanisms.
Main Results:
- Unduly acidic urine is increasingly recognized as a feature of metabolic syndrome in uric acid stone formers.
- Two primary abnormalities implicated are increased net acid excretion and impaired urinary ammonium excretion.
- These defects combine to create abnormally acidic urine, with emerging links to kidney insulin signaling.
Conclusions:
- Metabolic syndrome is associated with an increased risk of uric acid nephrolithiasis.
- Abnormal urinary acidity, driven by specific metabolic defects, is a key link.
- Further research into insulin signaling's role is warranted.
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